That is normal in the beginning. If the enemies have purple or even red health bars in an area then you should collect some resources to upgrade your stuff. https://www.powerpyx.com/god-of-war-ragnarok-what-does-health-bar-color-mean/

You literally just started the game. I assume you have at most a couple of hours in the game. If you feel that it is too hard just try to upgrade your gear or lower the difficulty. It is worth the pain and the many deaths. It gets actually just better and some aspects of the game will be harder :)